摘要
本工作研究了聚乙烯与光降解聚乙烯共混物的光氧化规律。实验中制备了含光降解程度不同的聚乙烯两系列共混物。累积光氧化时间相同时,共混物的断裂伸长率随前光氧化时间增加而增大,羰基生成量却随前光氧化时间增加而减少。热加工使光降解聚乙烯的力学性能有所恢复,这是因对结晶度发生影响所致,热加工时羰基生成的影响,主要由光降解程度不同时,不同分子结构聚合物的不同化学反应决定。选择不同光降解程度的低密度聚乙烯,通过共混二次加工,制备可予期户外使用寿命长的制品。用累积光氧化时间考察所得共混物的光氧化规律更有实际意义。
In order to recycle photodegraded low-density polyethylene(LDPE)bymelt-compounding,photooxidation of blends of LDPE and photodegraded LDPEwas investigated.Two series of LDPE blends were prepared.Elongation at break(Eb.)of the blends increased and the amount of car-bonyl formed(Cl)of the blends decreased with pre-photooxidation time atthe same accumulation time.It was shown that the change of Eb.was basedon the influence of melting on crystallinity and its morphology and the chan-ge of Cl mainly depended on the different chemical reactions of photodegradedLDPE of different structures during their melting.Accumulation photooxidation time method-an alternative method to studyphotooxidation of blends of LDPE and photodegraded LDPE—was presented.It is more effective for studying photooxidation of reprocessed LDPE.It ispossible to predict and control the outdoor life-time of recycled LDPE by se-lecting suitable melt-compounding programs.
出处
《中国塑料》
CAS
CSCD
1990年第4期32-38,共7页
China Plastics
